Families Affected by Progressive Neuromuscular Disorder Hold on to the Promise of Multiple Therapies

Evolving therapeutic options for spinal muscular atrophy (SMA) have provided hope for affected individuals and their families, slowing disease progression, helping patients achieve new milestones, and prolonging survival. Since 2016, the Food and Drug Administration has approved three disease-modifying therapies (DMTs) for the treatment of SMA in the United States. Following the approval of the first therapy, the Cure SMA organization has designed and sent out an annual Community Update Survey to gauge patients’ and caregivers’ familiarity with and preference for different therapeutic options, as well as factors involved in their decision-making process relating to changing therapies.

An analysis of results from the 2023 survey was designed to provide clinicians with an updated picture of the evolving therapeutic trends and preferences in the SMA community. The results, presented at the 2024 MDA Clinical and Scientific Conference in Orlando, Florida, showed that interest in combining different DMTs continues to grow, despite limited data about the safety and efficacy of combination therapy.

Nearly 700 surveys were completed between April and July 2023, with the final sample including 215 children and 222 adults with SMA based in the United States. A majority of affected individuals were treated with monotherapy (58%), followed by sequential therapy (29%) and combination therapy (12%). Combination therapy was defined as treatment with more than one DMT at the same time and included the addition of a therapy after gene replacement therapy (GRT). Sequential therapy was defined as receiving more than one DMT at different time points and included GRT given after discontinuing other DMTs. The main reason cited for using either sequential or combination therapies was an interest in trying a different DMT. Other reasons included physician recommendations, the desire to leave no stone unturned when it comes to SMA treatment, and a lack of improvement or loss of function.

The authors noted that the analysis was not designed to evaluate adverse events or efficacy of different treatments. Although more individuals indicated that they received sequential therapy than combination therapy, the findings showed that combination therapy has become a reality in the SMA community despite limited data about the long-term effects of therapies. “The results of this survey emphasize a call to action to recognize that combination treatment is occurring and we, as a research and clinical community, have an obligation to collect more data to analyze the safety and effectiveness of combination therapy,” the authors wrote.

Presenting author Lisa Belter, MPH, said that the trends and reasons for opting for sequential or combination therapies did not vary significantly from those reflected in the results of the 2022 survey. However, the 2024 survey, which will be dispatched next month, may paint a different picture as health literacy related to SMA continues to evolve and patients and caregivers become more familiar with therapeutic possibilities.